What is the Peppol Directory? How Does It Work? 

The Peppol Directory is the public “who’s who” of the Peppol network. It helps you find organisations that can exchange structured documents (such as e-invoicing documents) over Peppol and shows which document formats they can receive.

You can think of it as a searchable catalogue of Peppol participants. You can look up companies by name, country, Participant ID (endpoint ID), and the Peppol document types they support. What it does not do is deliver the documents itself. Delivery is handled behind the scenes by other Peppol components.

A key detail: publishing data to the Peppol Directory is done by Service Metadata Publishers (SMPs) and is not mandatory at the Peppol network level. An organisation can be fully live and routable on Peppol and still not appear in the public Directory. In that case, their SMP record exists and routing works, but no “business card” has been published to the Directory.

How Does the Peppol Directory Work?

Peppol uses a four-corner model. The Directory is only one piece of that model, and its job is discovery, not transport.

A simplified view of the flow:

1. You send a document (for example, an invoice) via your Peppol Access Point.
2. Your Access Point uses the Peppol Participant ID of the receiver as the address.
3. The Access Point consults the Service Metadata Locator (SML) – the global index that tells it which Service Metadata Publisher (SMP) holds information about that receiver.
4. The Access Point queries that SMP to get:
   • Which document types and versions the receiver can handle (their capabilities).
   • The technical endpoint where the document should be delivered.
5. The Access Point then sends the structured document to the receiver’s Access Point over the Peppol transport channel.

The Peppol Directory sits alongside this flow:

• It exposes a human-friendly, searchable view of who is on the network and what they can receive.
• It aggregates “business cards” from SMPs and makes them searchable by business users and automated tools.

So:

• The Directory helps people and systems find the right counterparty.
• The SML/SMP + Access Points handle routing and delivery.

What Are the Benefits of Being Listed in the Peppol Directory?

Being listed in the Peppol Directory is not just a technical detail. It has clear business value:

You are easier to find. Potential customers, suppliers, and public bodies can search the Directory by name, Participant ID, country or capability and immediately confirm that you are on Peppol and what you can receive.

Onboarding becomes faster. Instead of long email chains asking “Can you receive Peppol BIS Billing 3.0?” your partners can self-serve this information from your Directory entry and configure their systems accordingly.

You signal trust and readiness. A presence in the Directory, with a clearly defined Participant ID and capabilities, shows you are part of a governed, interoperable network rather than a one-off, custom connection.

You reduce mis-routing. When your Participant ID and supported document types are visible, partners are less likely to send the wrong formats or use incorrect identifiers, which avoids failed deliveries and manual rework.

You support automation. The Directory also offers a REST API, so your partners (or you) can automate discovery and keep master data in sync with live Directory information.

In short, a Directory entry turns you from “technically reachable” into “easily discoverable and simple to onboard.”

Is Registration in the Peppol Directory Mandatory?

At the OpenPeppol level, publishing a business card to the Peppol Directory is voluntary. The official specification explicitly notes that a drawback of the Directory is that publication of Business Cards is done on a voluntary basis.

However, you should be aware of two nuances:

• Some countries or communities may make it mandatory in their rules. For example, a national Peppol Authority, a public sector framework, or a large buyer community can require all participants in their scope to be visible in the Directory. There are already examples where publishing Business Cards is mandated for specific networks or jurisdictions.
• Directory visibility is separate from SML/SMP registration. An organisation can:
  • Be registered in SML/SMP (and thus fully routable on Peppol) without a Directory entry.
  • Have a Directory entry removed while still remaining in SML/SMP.

So the general rule is:

Network-wide Peppol policy: Directory listing is recommended but not required.

Local policy: Check whether your Peppol Authority, industry scheme, or key trading partners have made Directory publication mandatory as part of their onboarding rules.

How Secure is the Information in the Peppol Directory?

The Peppol Directory is intentionally designed as a public business directory. That has two important consequences:

1. It does not contain confidential transaction data.
   The Directory stores high-level “business card” information: name, country, optional identifiers, contact details, website and supported document types. It does not expose the content of invoices, purchase orders, or any sensitive financial data.
2. Updates are controlled via Peppol security infrastructure.
   • Only authorised SMPs or service providers can publish and update Business Cards.
   • Updates and deletions use authenticated APIs and Peppol certificates, aligned with Peppol’s wider transport security policies.

From a practical risk perspective:

• Treat the Directory like a public company profile. Do not publish information there that you would not also publish on your website or in a public supplier register.
• Make sure your SMP or service provider has clear internal processes for who can request changes, to avoid incorrect contact details or identifiers being exposed.

The Directory gives visibility, not secrecy. Security comes from the fact that it only exposes non-confidential data, and from the controlled way that data can be written and updated.

What Information Is Included in a Peppol Directory Entry?

Each entry in the Directory is built from a Business Card stored in an SMP. It usually includes two big groups of information:

1. Who the participant is (the “Business Card” details):
   • Company or organisation name
   • Country
   • Optional extra identifiers (e.g. VAT number, business registration number)
   • Address, website and contact details (where provided)
   • Registration or update dates
2. What the participant can receive (their “capabilities”):
   • Peppol document types and profiles they support, such as Peppol BIS Billing 3.0 or PINT-based formats
   • Versions of those documents (for example specific profile or process identifiers)

Behind the scenes, the Participant ID is the key field that ties everything together:

• It is the unique address that Peppol uses for routing.
• It follows the Peppol Policy for Identifiers, which defines how national IDs (VAT numbers, business numbers, GLNs, etc.) are embedded and which identifier schemes can be used.

A short technical note about formats:

• Peppol is a framework for structured XML business documents.
• PDF or CSV files can be attached as binary attachments to those XML documents (with a mime type and filename), but the XML is the canonical payload used for validation and automation. Attachments do not replace the structured document.

How Do You Get an Entry in the Peppol Directory? (Behind the Scenes)

From a network perspective, an entry in the Peppol Directory is the result of a three-step process: (RTC Suite)

1. Your organisation is registered in an SMP.
   Your Peppol service provider (often your Access Point or a linked SMP provider) creates and maintains your record in an SMP, including:
   • Your Participant ID
   • The document types and profiles you can send or receive
   • Your technical endpoint URL and certificates
2. Your Participant ID is published to the SML.
   The provider registers your Participant ID in the SML so that other Access Points can discover which SMP holds your metadata. This step is what makes you technically routable.
3. Your Business Card is optionally published to the Peppol Directory.
   • The SMP triggers an update to the Directory’s indexer using the official API.
   • The Directory reads your Business Card from the SMP and indexes it for search.

This last step—publishing the Business Card—is what turns your organisation from “routable in SML/SMP” into “discoverable in the public Directory.”

How Do You Add Your Company to the Peppol Directory? (In Practice)

From a business user’s perspective, you do not talk directly to the SML or the Directory API. Instead, the process usually looks like this:

1. Choose and onboard with a Peppol service provider.
   This might be an Access Point provider or a platform that includes SMP services.
2. Provide your master data.
   You share:
   • Your legal name and country
   • Your preferred Participant ID basis (for example, your VAT number or national company number)
   • Optional extra identifiers, address, website, and contact email
3. Ask them explicitly to publish you in the Peppol Directory.
   Many SMP user interfaces have a simple option such as “Publish in Peppol Directory”. When this is enabled:
   • Your Business Card is created or updated in the SMP.
   • The SMP pushes that Business Card into the Directory via the official API.
4. Verify your Directory entry.
   After publication, you can go to the public Directory website, search for your name or Participant ID, and confirm that:
   • The name and country are correct.
   • The identifiers and contact details are accurate.
   • The listed capabilities match what your systems can handle.

If something looks wrong, you do not edit it in the Directory itself. You ask your service provider to correct the Business Card in the SMP and re-publish.

Can You Remove Your Company from the Peppol Directory?

Yes. Being in the Directory and being in the Peppol network are two related but separate things.

• To remove your Directory entry, your SMP or service provider calls the Directory API to delete your Business Card. The Directory specification describes how SMPs should trigger updates, additions, and deletions.
• This does not automatically remove you from SML/SMP.
  Deleting the Business Card from the Directory is not the same as deleting or “dormant-ing” your Participant ID in the SML. Your organisation can remain routable on Peppol while being invisible in the public search, depending on your provider’s configuration.

In practical terms:

• If you want to disappear from the public Directory but stay technically reachable, ask your provider to remove or hide your Business Card.
• If you want to fully leave the Peppol network, you also need them to remove your Participant ID from SML and adjust your SMP records.

How Can You Search the Peppol Directory?

You can search the Peppol Directory through:

1. The public web interface at the official Directory URL.
   There, you can search by:
   • Company name
   • Peppol endpoint / Participant ID
   • Country
   • Document capability (e.g. Peppol BIS Billing 3.0)
     plus, in many cases, optional filters such as identifiers or contact details.
2. The REST API.
   For more advanced users, the Directory software exposes a REST search API that:
   • Lets you integrate Directory lookups into your own systems.
   • Supports automated queries for Participant IDs and capabilities at scale.

Common use cases:

• Checking whether a new supplier is already on Peppol and what they can receive.
• Confirming the correct Participant ID and format before sending the first live invoice.
• Regularly syncing your ERP or onboarding portal with Directory data for high-volume trading partners.

How to Use the Peppol Directory Effectively?

The safest pattern is:

1. Use the Directory as your front-door check.
   Before you start sending, look up your counterparty:
   • Confirm that the organisation you found really matches your customer or supplier.
   • Note their Participant ID and main document capabilities.
2. Store the Participant ID in your master data.
   Treat the Participant ID as a key field in your ERP or finance system, just like an IBAN or VAT number. Do not rely on free-text names or manually typed VAT numbers for routing.
3. Match documents to capabilities.
   Make sure that the invoice, order, or other document you plan to send matches one of the capabilities listed for that partner (for example, Peppol BIS Billing 3.0 with a specific process ID).
4. Let your Access Point handle discovery and delivery.
   After you’ve captured the correct Participant ID and chosen the right document profile, your Access Point will use SML and SMP to resolve the current endpoint and deliver the message.

This approach keeps the human part simple (look up and confirm), while letting the network machinery do the complicated routing work.

Practical Implementation Guidance for Onboarding and Change Management

A few concrete implementation tips that make life easier over time:

• Data governance.
  • Add a dedicated field for the Peppol Participant ID in your customer and supplier master records.
  • Add attributes for “Peppol capability set” (profile + version) so your ERP can automatically pick the correct format.
• Directory publication policy.
  • Decide as a company whether you want all Peppol-active entities to be visible in the Directory by default.
  • Instruct your provider to publish and maintain Business Cards accordingly and to update them promptly when your details change.
• SMP accuracy.
  • Check that your SMP entry has the correct endpoint URL, certificate, and technical contact details.
  • Remember: bad data in SMP leads to bad data in the Directory and failed deliveries.
• Attachments policy.
  • If business users insist on PDFs or other files, allow them as attachments but insist that the structured XML is always present and accurate.
  • Make it clear internally that Peppol is not “PDF by email with a different pipe”; it is structured data exchange.
• Diagnostics and support.
  • If a partner claims to be Peppol-live but you cannot find them in the Directory, ask them:
    • Which Participant ID they use.
    • Which provider/SMP they are with.
    • Whether their provider has published a Business Card to the Directory yet.

A Simple Analogy for Non-Technical Stakeholders

For non-technical colleagues, you can describe the Peppol Directory like this:

• The Directory is a public phone book: it lists organisations, the “number” they can be reached on (their Participant ID) and what kinds of “calls” they accept (their document capabilities).
• The SML and SMP together are the telecom switchboard: they make sure the call is routed to the right line.
• Your Access Point is your phone operator: it dials the number and completes the call on your behalf.

You look up the entry in the phone book once, save the number in your contacts, and then let the operator handle the mechanics of each call.

That is exactly how a well-implemented Peppol setup should feel for business users: simple, predictable, and boring—in a good way.

Sources

• Your original “Peppol Directory in Practice (2025)” draft and structure.
• Reviewer notes and requested headings / style changes.
• OpenPeppol Directory overview and public search fields. (OpenPeppol)

Peppol Directory implementation specification and architecture (Business Cards, voluntary publication, API). (docs.peppol.eu)

• Seeburger “How and why of the Peppol Directory” explainer (phone-book analogy and Business Card details). (SEEBURGER Blog)
• SMP provider documentation on “Publish in Peppol Directory” behaviour. (ion-smp.net)
• Peppol eDelivery documentation and identifier / business card schemas. (OpenPeppol)
• Example national annex making Directory support mandatory in a specific jurisdiction. (xoev.de)

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